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Suggestions for this Auger Motor Failure Analysis - Tests?

Discussion in 'Pellet Stoves, Pellet Fireplaces, Pellet Furnaces' started by don2222, Jan 26, 2014.

  1. don2222

    don2222

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    Hello

    I finally have a stove I am rebuilding where the Auger Motor failed after the stove fires up. The vacuum switch and vacuum hose was replaced and the High Limit switch tested in good working order with a brand new control board.

    Since all other components in the auger power circuit were good, I replaced the auger motor and the stove is running fine now.

    I really wish there was a meter I could put on the motor that showed a needle in the red or bad range?

    What is the next best test? Is there a good test that does not require thousands in test equipment?

    Is there a good way to measure the strength of the magnetic field? How worn the gears are in the gear box? etc?

    This 2 RPM Merkle-Korff Inc. gearbox auger motor was pulled from a Pelpro HHPP2BD approx 6 years old. MFD is not visible in pic

    Measuring torque may be a good way, but most of the tools I have seen for that are for a mechanics rachet.
    Since the Gleason-Avery has up to 250 in/lbs of torque, this would be a good number for comparison.

    Not sure if this tool would work? Looks like it would tighten down on the auger motor shaft? Then what?
    http://www.globalindustrial.com/p/t...Force/economical-torque-gauge-50ozin-capacity

    I was thinking of measuring the strenght of the electromagnetic field?
    This would tell if the coil windings were breaking down or shorting.
    This would be related to torque, however any worn gears would not show up.
    Not too expensive.
    http://www.casa.com/p/extech-480823...099411&utm_content=pla&adtype=pla&cagpspn=pla

    How about one of those Kill-A-Watt meters?

    See pics below
    Click to Enlarge
     

    Attached Files:

    Last edited: Jan 26, 2014
  2. don2222

    don2222

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    I found the Kill-A-Watt meter and checked the instructions to see what measurements it makes. The amp scale is very good

    Volts are displayed in Volts (true RMS), Current is displayed in Amps (true RMS), Watts are displayed in active power Watts, VA is displayed in apparent power VA (VA=Vrms*Arms), Frequency is displayed in Hertz (Hz), Power Factor (P.F.) is displayed as (Watts/Vrms*Arms).

    I just plugged a 14 watt CFL rated at 0.23 amps
    As a baseline for reference:
    It measured 0.20 amps at 119.0 volts with P.F of 6.1 at 60 HZ @ 22.1 VA for 13.5 watts on the watt meter!

    Well, I just measured the failed Auger Motor
    It measured 0.01 Amps at 119.1 volts with P.F. of 0.41 at 60 Hz @ 1.2 VA for 0.4 watts on the meter

    Problem is that a new motor had just about the same values. No smoking gun here.
    Seems like the values are so low that there is not much different.
     
    Last edited: Jan 26, 2014
  3. don2222

    don2222

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    Hello

    Maybe going with a consulting service like G2 Consulting for Motor Torgue Testing and Dynomometer for small motors?
    http://www.consult-g2.com/

    Or

    Maybe consuting on failure analysis
    http://www.tribology.co.uk/services/investigate/index.htm

    In this case the failure seems to be due to Thermal Instability
    This failure mode occurs when a large temperature difference builds up between the shaft inside a bearing and the housing surrounding the bearing. The differential thermal expansion causes the bearing to lose internal clearance and become pre-loaded. This results in increased heat generation which will increase the differential temperature. This is positive feedback which rapidly leads to thermal runaway and melt-down.

    Click on pic below to enlarge:
     

    Attached Files:

    Last edited: Jan 26, 2014